Question

Waves and phase difference

Two identical waves with wavelength \(617\,[\text{nm}]\) and the same phase constant, pass through \(2.2\,[\text{mm}]\) of different glass materials. One material's refractive index is \(1.8\), while the other material has a refractive index of \(1.2\). After both waves exit from the respective materials, the magnitude of the phase angle difference in units of radians between the two waves is: